78 re;ports of investigations and projects. 



From October 15, 1906, until January 4, 1907, and from February 11 until 

 June 10, 1907, I was absent from the Station on account of the work under- 

 taken by the Institution relative to Mr. Burbank's valuable horticultural 

 operations. During these periods the above-mentioned pedigree cultures 

 were under the care and observation of Dr. E. N. Transeau. 



Breeding Strains of Insects. — F. E. Lnta. 



Much time during the past year has been spent in studies of heredity with 

 Drosophila ampelophila as material. As yet, the work on the inheritance 

 of the duration of the egg-larval and pupal periods has not yielded definite 

 results. The same is true of the activity of response to light. A morpholog- 

 ical character — abnormal wing-veins — has proved to be inherited in a very 

 interesting fashion. A prelimiinary account of this latter piece of work was 

 given at the Seventh International Zoological Congress. It is hoped that 

 a final report will be possible shortly. 



The breeding of Grylhis was quite successful this season, and 125 pairs 

 have been mated for next season's work. It was found this season that the 

 inheritance of the dimorphic wing-length is not a case of simple Mendelism, 

 as had been supposed, and many of the new matings have been arranged with 

 reference to this character. A new form, having aborted tegmina, wings, 

 and ovipositor, has appeared in my pedigreed stock. The inheritance of this 

 condition is being tested. Male crickets usually have the right tegmen over- 

 lapping the left, but some maintain the reversed position. The inheritance 

 of the unusual position is being tested. A somewhat similar character is 

 found in man. When the hands are clasped together there is usually a per- 

 fect constancy as to which thumb is uppermost ; but some people always put 

 the right uppermost, others the left. I hope to find out if this character is 

 inherited and, if so, what laws are followed. 



The work with Crioceris, Hyphantria, and Spilosoma has been continued, 

 but it has not been pushed vigorously on account of lack of time. 



Cell-studies in Heredity. — Anne M. Liitz. 



The greater portion of the past year has been occupied with the study of 

 the somatic cells of the Oenotheras, which was undertaken as a preliminary 

 to future work upon the germ-cells. This has proven a subject of such un- 

 expected interest, however, that work will be continued, for the present at 

 least, upon somatic tissue exclusively. An exceptional opportunity is offered 

 for such work at the Station for Experimental Evolution, inasmuch as 

 pedigreed cultures derived from pure-bred seed obtained from de Vries 

 and MacDougal have been under cultivation here for three generations. 

 Work was begun upon the growing root-tips of pot-bound greenhouse plants 

 in the rosette stage, and the following forms have been studied and were 

 reported upon at the Seventh International Zoological Congress : 



Self -fertilized: Oenothera lamarckiana, O. gigas, O. lata. 



Arose from sclf-pollinatcd O. lata: O. nanella, O. oblonga, O. lamarckiana. 



Open pollinated: O. rubrinervis, O. lamarckiana. 



Guarded hybrid: O. lata X O. gigas. 



Dr. MacDougal gave us the lata, nanella, oblonga, and lamarckiana, above 

 referred to, all of which were first-generation oft'spring of self-pollinated lata 

 arising as a mutant from lamarckiana. O. lata was of especial interest. 



